Add "muxcover -freedecode"

Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/passes/techmap/muxcover.cc b/passes/techmap/muxcover.cc
index e952b04b649bcbfb0993e9c674c8b41bab4912ff..7fa89bbe34b4694f91a0934ad071fb67d7a43d9e 100644 (file)
--- a/passes/techmap/muxcover.cc
+++ b/passes/techmap/muxcover.cc
@@ -57,6 +57,7 @@ struct MuxcoverWorker
        bool use_mux8;
        bool use_mux16;
        bool nodecode;
+       bool freedecode;
        bool nopartial;
 
        int cost_mux2;
@@ -70,6 +71,7 @@ struct MuxcoverWorker
                use_mux8 = false;
                use_mux16 = false;
                nodecode = false;
+               freedecode = false;
                nopartial = false;
                cost_mux2 = COST_MUX2;
                cost_mux4 = COST_MUX4;
@@ -178,6 +180,9 @@ struct MuxcoverWorker
                if (A == State::Sx || B == State::Sx)
                        return 0;
 
+               if (freedecode)
+                       return 0;
+
                return std::max((cost_mux2 / GetSize(std::get<1>(entry))) - 1, 1);
        }
 
@@ -620,6 +625,9 @@ struct MuxcoverPass : public Pass {
                log("        substitutions, but guarantees that the resulting circuit is not\n");
                log("        less efficient than the original circuit.\n");
                log("\n");
+               log("    -freedecode\n");
+               log("        Do not count cost for generated decode logic\n");
+               log("\n");
                log("    -nopartial\n");
                log("        Do not consider mappings that use $_MUX<N>_ to select from less\n");
                log("        than <N> different signals.\n");
@@ -633,6 +641,7 @@ struct MuxcoverPass : public Pass {
                bool use_mux8 = false;
                bool use_mux16 = false;
                bool nodecode = false;
+               bool freedecode = false;
                bool nopartial = false;
                int cost_mux4 = COST_MUX4;
                int cost_mux8 = COST_MUX8;
@@ -670,6 +679,10 @@ struct MuxcoverPass : public Pass {
                                nodecode = true;
                                continue;
                        }
+                       if (arg == "-freedecode") {
+                               freedecode = true;
+                               continue;
+                       }
                        if (arg == "-nopartial") {
                                nopartial = true;
                                continue;
@@ -694,6 +707,7 @@ struct MuxcoverPass : public Pass {
                        worker.cost_mux8 = cost_mux8;
                        worker.cost_mux16 = cost_mux16;
                        worker.nodecode = nodecode;
+                       worker.freedecode = freedecode;
                        worker.nopartial = nopartial;
                        worker.run();
                }